2 * kexec: kexec_file_load system call
4 * Copyright (C) 2014 Red Hat Inc.
6 * Vivek Goyal <vgoyal@redhat.com>
8 * This source code is licensed under the GNU General Public License,
9 * Version 2. See the file COPYING for more details.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/capability.h>
16 #include <linux/file.h>
17 #include <linux/slab.h>
18 #include <linux/kexec.h>
19 #include <linux/mutex.h>
20 #include <linux/list.h>
21 #include <crypto/hash.h>
22 #include <crypto/sha.h>
23 #include <linux/syscalls.h>
24 #include <linux/vmalloc.h>
25 #include "kexec_internal.h"
28 * Declare these symbols weak so that if architecture provides a purgatory,
29 * these will be overridden.
31 char __weak kexec_purgatory[0];
32 size_t __weak kexec_purgatory_size = 0;
34 static int kexec_calculate_store_digests(struct kimage *image);
36 static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
38 struct fd f = fdget(fd);
47 ret = vfs_getattr(&f.file->f_path, &stat);
51 if (stat.size > INT_MAX) {
56 /* Don't hand 0 to vmalloc, it whines. */
62 *buf = vmalloc(stat.size);
69 while (pos < stat.size) {
70 bytes = kernel_read(f.file, pos, (char *)(*buf) + pos,
83 if (pos != stat.size) {
95 /* Architectures can provide this probe function */
96 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
97 unsigned long buf_len)
102 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
104 return ERR_PTR(-ENOEXEC);
107 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
112 #ifdef CONFIG_KEXEC_VERIFY_SIG
113 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
114 unsigned long buf_len)
116 return -EKEYREJECTED;
120 /* Apply relocations of type RELA */
122 arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
125 pr_err("RELA relocation unsupported.\n");
129 /* Apply relocations of type REL */
131 arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
134 pr_err("REL relocation unsupported.\n");
139 * Free up memory used by kernel, initrd, and command line. This is temporary
140 * memory allocation which is not needed any more after these buffers have
141 * been loaded into separate segments and have been copied elsewhere.
143 void kimage_file_post_load_cleanup(struct kimage *image)
145 struct purgatory_info *pi = &image->purgatory_info;
147 vfree(image->kernel_buf);
148 image->kernel_buf = NULL;
150 vfree(image->initrd_buf);
151 image->initrd_buf = NULL;
153 kfree(image->cmdline_buf);
154 image->cmdline_buf = NULL;
156 vfree(pi->purgatory_buf);
157 pi->purgatory_buf = NULL;
162 /* See if architecture has anything to cleanup post load */
163 arch_kimage_file_post_load_cleanup(image);
166 * Above call should have called into bootloader to free up
167 * any data stored in kimage->image_loader_data. It should
168 * be ok now to free it up.
170 kfree(image->image_loader_data);
171 image->image_loader_data = NULL;
175 * In file mode list of segments is prepared by kernel. Copy relevant
176 * data from user space, do error checking, prepare segment list
179 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
180 const char __user *cmdline_ptr,
181 unsigned long cmdline_len, unsigned flags)
186 ret = copy_file_from_fd(kernel_fd, &image->kernel_buf,
187 &image->kernel_buf_len);
191 /* Call arch image probe handlers */
192 ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
193 image->kernel_buf_len);
198 #ifdef CONFIG_KEXEC_VERIFY_SIG
199 ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
200 image->kernel_buf_len);
202 pr_debug("kernel signature verification failed.\n");
205 pr_debug("kernel signature verification successful.\n");
207 /* It is possible that there no initramfs is being loaded */
208 if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
209 ret = copy_file_from_fd(initrd_fd, &image->initrd_buf,
210 &image->initrd_buf_len);
216 image->cmdline_buf = kzalloc(cmdline_len, GFP_KERNEL);
217 if (!image->cmdline_buf) {
222 ret = copy_from_user(image->cmdline_buf, cmdline_ptr,
229 image->cmdline_buf_len = cmdline_len;
231 /* command line should be a string with last byte null */
232 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
238 /* Call arch image load handlers */
239 ldata = arch_kexec_kernel_image_load(image);
242 ret = PTR_ERR(ldata);
246 image->image_loader_data = ldata;
248 /* In case of error, free up all allocated memory in this function */
250 kimage_file_post_load_cleanup(image);
255 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
256 int initrd_fd, const char __user *cmdline_ptr,
257 unsigned long cmdline_len, unsigned long flags)
260 struct kimage *image;
261 bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
263 image = do_kimage_alloc_init();
267 image->file_mode = 1;
269 if (kexec_on_panic) {
270 /* Enable special crash kernel control page alloc policy. */
271 image->control_page = crashk_res.start;
272 image->type = KEXEC_TYPE_CRASH;
275 ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
276 cmdline_ptr, cmdline_len, flags);
280 ret = sanity_check_segment_list(image);
282 goto out_free_post_load_bufs;
285 image->control_code_page = kimage_alloc_control_pages(image,
286 get_order(KEXEC_CONTROL_PAGE_SIZE));
287 if (!image->control_code_page) {
288 pr_err("Could not allocate control_code_buffer\n");
289 goto out_free_post_load_bufs;
292 if (!kexec_on_panic) {
293 image->swap_page = kimage_alloc_control_pages(image, 0);
294 if (!image->swap_page) {
295 pr_err("Could not allocate swap buffer\n");
296 goto out_free_control_pages;
302 out_free_control_pages:
303 kimage_free_page_list(&image->control_pages);
304 out_free_post_load_bufs:
305 kimage_file_post_load_cleanup(image);
311 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
312 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
313 unsigned long, flags)
316 struct kimage **dest_image, *image;
318 /* We only trust the superuser with rebooting the system. */
319 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
322 /* Make sure we have a legal set of flags */
323 if (flags != (flags & KEXEC_FILE_FLAGS))
328 if (!mutex_trylock(&kexec_mutex))
331 dest_image = &kexec_image;
332 if (flags & KEXEC_FILE_ON_CRASH)
333 dest_image = &kexec_crash_image;
335 if (flags & KEXEC_FILE_UNLOAD)
339 * In case of crash, new kernel gets loaded in reserved region. It is
340 * same memory where old crash kernel might be loaded. Free any
341 * current crash dump kernel before we corrupt it.
343 if (flags & KEXEC_FILE_ON_CRASH)
344 kimage_free(xchg(&kexec_crash_image, NULL));
346 ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
351 ret = machine_kexec_prepare(image);
355 ret = kexec_calculate_store_digests(image);
359 for (i = 0; i < image->nr_segments; i++) {
360 struct kexec_segment *ksegment;
362 ksegment = &image->segment[i];
363 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
364 i, ksegment->buf, ksegment->bufsz, ksegment->mem,
367 ret = kimage_load_segment(image, &image->segment[i]);
372 kimage_terminate(image);
375 * Free up any temporary buffers allocated which are not needed
376 * after image has been loaded
378 kimage_file_post_load_cleanup(image);
380 image = xchg(dest_image, image);
382 mutex_unlock(&kexec_mutex);
387 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
388 struct kexec_buf *kbuf)
390 struct kimage *image = kbuf->image;
391 unsigned long temp_start, temp_end;
393 temp_end = min(end, kbuf->buf_max);
394 temp_start = temp_end - kbuf->memsz;
397 /* align down start */
398 temp_start = temp_start & (~(kbuf->buf_align - 1));
400 if (temp_start < start || temp_start < kbuf->buf_min)
403 temp_end = temp_start + kbuf->memsz - 1;
406 * Make sure this does not conflict with any of existing
409 if (kimage_is_destination_range(image, temp_start, temp_end)) {
410 temp_start = temp_start - PAGE_SIZE;
414 /* We found a suitable memory range */
418 /* If we are here, we found a suitable memory range */
419 kbuf->mem = temp_start;
421 /* Success, stop navigating through remaining System RAM ranges */
425 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
426 struct kexec_buf *kbuf)
428 struct kimage *image = kbuf->image;
429 unsigned long temp_start, temp_end;
431 temp_start = max(start, kbuf->buf_min);
434 temp_start = ALIGN(temp_start, kbuf->buf_align);
435 temp_end = temp_start + kbuf->memsz - 1;
437 if (temp_end > end || temp_end > kbuf->buf_max)
440 * Make sure this does not conflict with any of existing
443 if (kimage_is_destination_range(image, temp_start, temp_end)) {
444 temp_start = temp_start + PAGE_SIZE;
448 /* We found a suitable memory range */
452 /* If we are here, we found a suitable memory range */
453 kbuf->mem = temp_start;
455 /* Success, stop navigating through remaining System RAM ranges */
459 static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
461 struct kexec_buf *kbuf = (struct kexec_buf *)arg;
462 unsigned long sz = end - start + 1;
464 /* Returning 0 will take to next memory range */
465 if (sz < kbuf->memsz)
468 if (end < kbuf->buf_min || start > kbuf->buf_max)
472 * Allocate memory top down with-in ram range. Otherwise bottom up
476 return locate_mem_hole_top_down(start, end, kbuf);
477 return locate_mem_hole_bottom_up(start, end, kbuf);
481 * Helper function for placing a buffer in a kexec segment. This assumes
482 * that kexec_mutex is held.
484 int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
485 unsigned long memsz, unsigned long buf_align,
486 unsigned long buf_min, unsigned long buf_max,
487 bool top_down, unsigned long *load_addr)
490 struct kexec_segment *ksegment;
491 struct kexec_buf buf, *kbuf;
494 /* Currently adding segment this way is allowed only in file mode */
495 if (!image->file_mode)
498 if (image->nr_segments >= KEXEC_SEGMENT_MAX)
502 * Make sure we are not trying to add buffer after allocating
503 * control pages. All segments need to be placed first before
504 * any control pages are allocated. As control page allocation
505 * logic goes through list of segments to make sure there are
506 * no destination overlaps.
508 if (!list_empty(&image->control_pages)) {
513 memset(&buf, 0, sizeof(struct kexec_buf));
516 kbuf->buffer = buffer;
519 kbuf->memsz = ALIGN(memsz, PAGE_SIZE);
520 kbuf->buf_align = max(buf_align, PAGE_SIZE);
521 kbuf->buf_min = buf_min;
522 kbuf->buf_max = buf_max;
523 kbuf->top_down = top_down;
525 /* Walk the RAM ranges and allocate a suitable range for the buffer */
526 if (image->type == KEXEC_TYPE_CRASH)
527 ret = walk_iomem_res("Crash kernel",
528 IORESOURCE_MEM | IORESOURCE_BUSY,
529 crashk_res.start, crashk_res.end, kbuf,
530 locate_mem_hole_callback);
532 ret = walk_system_ram_res(0, -1, kbuf,
533 locate_mem_hole_callback);
535 /* A suitable memory range could not be found for buffer */
536 return -EADDRNOTAVAIL;
539 /* Found a suitable memory range */
540 ksegment = &image->segment[image->nr_segments];
541 ksegment->kbuf = kbuf->buffer;
542 ksegment->bufsz = kbuf->bufsz;
543 ksegment->mem = kbuf->mem;
544 ksegment->memsz = kbuf->memsz;
545 image->nr_segments++;
546 *load_addr = ksegment->mem;
550 /* Calculate and store the digest of segments */
551 static int kexec_calculate_store_digests(struct kimage *image)
553 struct crypto_shash *tfm;
554 struct shash_desc *desc;
555 int ret = 0, i, j, zero_buf_sz, sha_region_sz;
556 size_t desc_size, nullsz;
559 struct kexec_sha_region *sha_regions;
560 struct purgatory_info *pi = &image->purgatory_info;
562 zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
563 zero_buf_sz = PAGE_SIZE;
565 tfm = crypto_alloc_shash("sha256", 0, 0);
571 desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
572 desc = kzalloc(desc_size, GFP_KERNEL);
578 sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
579 sha_regions = vzalloc(sha_region_sz);
586 ret = crypto_shash_init(desc);
588 goto out_free_sha_regions;
590 digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
593 goto out_free_sha_regions;
596 for (j = i = 0; i < image->nr_segments; i++) {
597 struct kexec_segment *ksegment;
599 ksegment = &image->segment[i];
601 * Skip purgatory as it will be modified once we put digest
604 if (ksegment->kbuf == pi->purgatory_buf)
607 ret = crypto_shash_update(desc, ksegment->kbuf,
613 * Assume rest of the buffer is filled with zero and
614 * update digest accordingly.
616 nullsz = ksegment->memsz - ksegment->bufsz;
618 unsigned long bytes = nullsz;
620 if (bytes > zero_buf_sz)
622 ret = crypto_shash_update(desc, zero_buf, bytes);
631 sha_regions[j].start = ksegment->mem;
632 sha_regions[j].len = ksegment->memsz;
637 ret = crypto_shash_final(desc, digest);
639 goto out_free_digest;
640 ret = kexec_purgatory_get_set_symbol(image, "sha_regions",
641 sha_regions, sha_region_sz, 0);
643 goto out_free_digest;
645 ret = kexec_purgatory_get_set_symbol(image, "sha256_digest",
646 digest, SHA256_DIGEST_SIZE, 0);
648 goto out_free_digest;
653 out_free_sha_regions:
663 /* Actually load purgatory. Lot of code taken from kexec-tools */
664 static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
665 unsigned long max, int top_down)
667 struct purgatory_info *pi = &image->purgatory_info;
668 unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad;
669 unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset;
670 unsigned char *buf_addr, *src;
671 int i, ret = 0, entry_sidx = -1;
672 const Elf_Shdr *sechdrs_c;
673 Elf_Shdr *sechdrs = NULL;
674 void *purgatory_buf = NULL;
677 * sechdrs_c points to section headers in purgatory and are read
678 * only. No modifications allowed.
680 sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff;
683 * We can not modify sechdrs_c[] and its fields. It is read only.
684 * Copy it over to a local copy where one can store some temporary
685 * data and free it at the end. We need to modify ->sh_addr and
686 * ->sh_offset fields to keep track of permanent and temporary
687 * locations of sections.
689 sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr));
693 memcpy(sechdrs, sechdrs_c, pi->ehdr->e_shnum * sizeof(Elf_Shdr));
696 * We seem to have multiple copies of sections. First copy is which
697 * is embedded in kernel in read only section. Some of these sections
698 * will be copied to a temporary buffer and relocated. And these
699 * sections will finally be copied to their final destination at
702 * Use ->sh_offset to reflect section address in memory. It will
703 * point to original read only copy if section is not allocatable.
704 * Otherwise it will point to temporary copy which will be relocated.
706 * Use ->sh_addr to contain final address of the section where it
707 * will go during execution time.
709 for (i = 0; i < pi->ehdr->e_shnum; i++) {
710 if (sechdrs[i].sh_type == SHT_NOBITS)
713 sechdrs[i].sh_offset = (unsigned long)pi->ehdr +
714 sechdrs[i].sh_offset;
718 * Identify entry point section and make entry relative to section
721 entry = pi->ehdr->e_entry;
722 for (i = 0; i < pi->ehdr->e_shnum; i++) {
723 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
726 if (!(sechdrs[i].sh_flags & SHF_EXECINSTR))
729 /* Make entry section relative */
730 if (sechdrs[i].sh_addr <= pi->ehdr->e_entry &&
731 ((sechdrs[i].sh_addr + sechdrs[i].sh_size) >
732 pi->ehdr->e_entry)) {
734 entry -= sechdrs[i].sh_addr;
739 /* Determine how much memory is needed to load relocatable object. */
745 for (i = 0; i < pi->ehdr->e_shnum; i++) {
746 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
749 align = sechdrs[i].sh_addralign;
750 if (sechdrs[i].sh_type != SHT_NOBITS) {
751 if (buf_align < align)
753 buf_sz = ALIGN(buf_sz, align);
754 buf_sz += sechdrs[i].sh_size;
757 if (bss_align < align)
759 bss_sz = ALIGN(bss_sz, align);
760 bss_sz += sechdrs[i].sh_size;
764 /* Determine the bss padding required to align bss properly */
766 if (buf_sz & (bss_align - 1))
767 bss_pad = bss_align - (buf_sz & (bss_align - 1));
769 memsz = buf_sz + bss_pad + bss_sz;
771 /* Allocate buffer for purgatory */
772 purgatory_buf = vzalloc(buf_sz);
773 if (!purgatory_buf) {
778 if (buf_align < bss_align)
779 buf_align = bss_align;
781 /* Add buffer to segment list */
782 ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz,
783 buf_align, min, max, top_down,
784 &pi->purgatory_load_addr);
788 /* Load SHF_ALLOC sections */
789 buf_addr = purgatory_buf;
790 load_addr = curr_load_addr = pi->purgatory_load_addr;
791 bss_addr = load_addr + buf_sz + bss_pad;
793 for (i = 0; i < pi->ehdr->e_shnum; i++) {
794 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
797 align = sechdrs[i].sh_addralign;
798 if (sechdrs[i].sh_type != SHT_NOBITS) {
799 curr_load_addr = ALIGN(curr_load_addr, align);
800 offset = curr_load_addr - load_addr;
801 /* We already modifed ->sh_offset to keep src addr */
802 src = (char *) sechdrs[i].sh_offset;
803 memcpy(buf_addr + offset, src, sechdrs[i].sh_size);
805 /* Store load address and source address of section */
806 sechdrs[i].sh_addr = curr_load_addr;
809 * This section got copied to temporary buffer. Update
810 * ->sh_offset accordingly.
812 sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset);
814 /* Advance to the next address */
815 curr_load_addr += sechdrs[i].sh_size;
817 bss_addr = ALIGN(bss_addr, align);
818 sechdrs[i].sh_addr = bss_addr;
819 bss_addr += sechdrs[i].sh_size;
823 /* Update entry point based on load address of text section */
825 entry += sechdrs[entry_sidx].sh_addr;
827 /* Make kernel jump to purgatory after shutdown */
828 image->start = entry;
830 /* Used later to get/set symbol values */
831 pi->sechdrs = sechdrs;
834 * Used later to identify which section is purgatory and skip it
837 pi->purgatory_buf = purgatory_buf;
841 vfree(purgatory_buf);
845 static int kexec_apply_relocations(struct kimage *image)
848 struct purgatory_info *pi = &image->purgatory_info;
849 Elf_Shdr *sechdrs = pi->sechdrs;
851 /* Apply relocations */
852 for (i = 0; i < pi->ehdr->e_shnum; i++) {
853 Elf_Shdr *section, *symtab;
855 if (sechdrs[i].sh_type != SHT_RELA &&
856 sechdrs[i].sh_type != SHT_REL)
860 * For section of type SHT_RELA/SHT_REL,
861 * ->sh_link contains section header index of associated
862 * symbol table. And ->sh_info contains section header
863 * index of section to which relocations apply.
865 if (sechdrs[i].sh_info >= pi->ehdr->e_shnum ||
866 sechdrs[i].sh_link >= pi->ehdr->e_shnum)
869 section = &sechdrs[sechdrs[i].sh_info];
870 symtab = &sechdrs[sechdrs[i].sh_link];
872 if (!(section->sh_flags & SHF_ALLOC))
876 * symtab->sh_link contain section header index of associated
879 if (symtab->sh_link >= pi->ehdr->e_shnum)
880 /* Invalid section number? */
884 * Respective architecture needs to provide support for applying
885 * relocations of type SHT_RELA/SHT_REL.
887 if (sechdrs[i].sh_type == SHT_RELA)
888 ret = arch_kexec_apply_relocations_add(pi->ehdr,
890 else if (sechdrs[i].sh_type == SHT_REL)
891 ret = arch_kexec_apply_relocations(pi->ehdr,
900 /* Load relocatable purgatory object and relocate it appropriately */
901 int kexec_load_purgatory(struct kimage *image, unsigned long min,
902 unsigned long max, int top_down,
903 unsigned long *load_addr)
905 struct purgatory_info *pi = &image->purgatory_info;
908 if (kexec_purgatory_size <= 0)
911 if (kexec_purgatory_size < sizeof(Elf_Ehdr))
914 pi->ehdr = (Elf_Ehdr *)kexec_purgatory;
916 if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0
917 || pi->ehdr->e_type != ET_REL
918 || !elf_check_arch(pi->ehdr)
919 || pi->ehdr->e_shentsize != sizeof(Elf_Shdr))
922 if (pi->ehdr->e_shoff >= kexec_purgatory_size
923 || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) >
924 kexec_purgatory_size - pi->ehdr->e_shoff))
927 ret = __kexec_load_purgatory(image, min, max, top_down);
931 ret = kexec_apply_relocations(image);
935 *load_addr = pi->purgatory_load_addr;
939 vfree(pi->purgatory_buf);
943 static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
952 if (!pi->sechdrs || !pi->ehdr)
955 sechdrs = pi->sechdrs;
958 for (i = 0; i < ehdr->e_shnum; i++) {
959 if (sechdrs[i].sh_type != SHT_SYMTAB)
962 if (sechdrs[i].sh_link >= ehdr->e_shnum)
963 /* Invalid strtab section number */
965 strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset;
966 syms = (Elf_Sym *)sechdrs[i].sh_offset;
968 /* Go through symbols for a match */
969 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
970 if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
973 if (strcmp(strtab + syms[k].st_name, name) != 0)
976 if (syms[k].st_shndx == SHN_UNDEF ||
977 syms[k].st_shndx >= ehdr->e_shnum) {
978 pr_debug("Symbol: %s has bad section index %d.\n",
979 name, syms[k].st_shndx);
983 /* Found the symbol we are looking for */
991 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
993 struct purgatory_info *pi = &image->purgatory_info;
997 sym = kexec_purgatory_find_symbol(pi, name);
999 return ERR_PTR(-EINVAL);
1001 sechdr = &pi->sechdrs[sym->st_shndx];
1004 * Returns the address where symbol will finally be loaded after
1005 * kexec_load_segment()
1007 return (void *)(sechdr->sh_addr + sym->st_value);
1011 * Get or set value of a symbol. If "get_value" is true, symbol value is
1012 * returned in buf otherwise symbol value is set based on value in buf.
1014 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1015 void *buf, unsigned int size, bool get_value)
1019 struct purgatory_info *pi = &image->purgatory_info;
1022 sym = kexec_purgatory_find_symbol(pi, name);
1026 if (sym->st_size != size) {
1027 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1028 name, (unsigned long)sym->st_size, size);
1032 sechdrs = pi->sechdrs;
1034 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1035 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1036 get_value ? "get" : "set");
1040 sym_buf = (unsigned char *)sechdrs[sym->st_shndx].sh_offset +
1044 memcpy((void *)buf, sym_buf, size);
1046 memcpy((void *)sym_buf, buf, size);